Method and apparatus for classifying abrasives suspended in liquids



June 27, 1933. BERGUERAND 1,916,035

METHOD AND NPBRPTUS FQR ILASSIFYING ABRASIVES SUSPENDED IN LIQUIDS Filed May 25, 1926 gnmntoz Patented June 27, 1933 UNETED STATES PATENT. GFFICE- LUCIEN BERGUERAND, OF STOLBERG, GERMANY, ASSIGNOR T0 SOCIETE ANONYME DES MANUFACTURES DIES GLACES & PRODUITS CHIMIQUES DE SAINT-GOBAIN, CHAUNY & CIREY, OF PARIS, FRANCE METHOD AND APPARATUS FOR CLASSIFYING ABRASIVES SUSPENDED IIV LIQUIDS Application filed May 25, 1926, Serial No. 111,649, and in Germany May 28, 1925.

The present invention has for its purpose I to provide a method and apparatus forclassirindin machines. {I s Solid particles are generally separated out of the liquid material in which they are suspended by the combined effect of gravity,of the specific resistance of said liquid and of the speed at which it moves, the proportion between the particles deposited and the particles that remain suspended varying with the size of the particles and the speed of the liquid in which they are carried.

Consequently,'in order to obtain the separation of particles of determined size, it is necessary to control the speed 'of the liquid in which they are suspended and to render that speed as uniform as possible in all parts of any horizontal section of said liquid.

This object has been realized in my inven-' tion, by moving the liquid with the. particles suspended therein through a succession of depositing vessels or grading tanks, without the addition of any other liquid, the volume of the liquid which passes through each vessel during the same time being controlled in order to obtain in successive vessels decreasing velocities for the depositofwparticlcs of decreasing size from the liquid carrying the particles. This is accomplished by feeding the liquid into each vessel through an overflow in order to regulate the velocity of the liquid for the deposit of each size of particles and also by feeding the liquid upwardly to a series of vertical or inclined parallel channels of such restricted cross section that variations in the velocity of the liquid in cach channel and the formation of eddy currents is prevented, both of which would cause deposits of particles of different sizes.

'ticles are carried on with the In the drawing forming part of this specification,-

Figure 1 illustrates a separating vat embodymg my invention.

Figure 2 is a horizontal section of Figure 1. V

Figure 3 shows a series of separating vats like that shown in Figure 1.

In the drawing, A designates a vat, the lower part of which forms a funnel B. The vat contains a series of parallel partitions C, vertical or inclined, preferably undulating, the apices of which abut,forming a honeycomb, through the undulations of which the l quid carrying the solid particles rises, the llqllld being fed into the" funnel B, near its bottom, through the pipe D, passing from the funnel upwardly through. the several channels'formed by the partitions C, and discharging into the out-flow F. The coarser solid particles fail to rise with the liquid in the-channels, and drop to the bottom of the funnel B, from which they are evacuated through the outlet E, while the-finer par- The coarsest particles being separated out and remaining in vat A the liquid containa ing liner particles is fed through out-flow F liquid through into receptacle G and conveyed through tube D into funnel B of the second vat A which extracts a part of these particles, while still finer particles are extracted invat A While I have only shown three vats, any number of vats can be connected in series so as to extract from the liquid, the particles in proper order, and to the desired degree of fineness. i

The size of particles separated out in each vat is determined by the rate of rise of the liquid, which rate is regulated by controlling the amount passing through tubes D D D outlets E E E; and outflows F F F This control is obtained by maintaining constant the level in liquid in receptacles G G2 G, by means of overflows H H H and regulating the issue of solid particles through outlets E E 15 It will be seen that the height of over-flows in relation to the out-flows F F, F regulates the head pressure in their respective vats, the excess liquid which would cause increased head pressure and hence increased speed being discharged through these openings.

Besides, I contemplate connecting at outlets E E E devices for regulating-density like that shown in French Patent 593,937.

Having thus described my invention what I claim as new, and desire to secure by Letters Patent is 1. In an apparatus for classifying solid particles and depositing the same from a liquid by which they are carried, a vessel having a series of undulating parallel partitions having their apices in contact to form a series of parallel passages of restricted cross section, in combination with means for feeding the liquid below the partitions and with-drawing it from above thesame, means for controlling the hydrostatic head between the feed and withdrawal points, and means for regulating the density of the classified material.

2. The method of classifying out of liquid solid particles suspended therein which oomprises causing the same to flow upwardly in the vessel to an overflow near the top thereof, withdrawing from the base of the vessel particles deposited in the upward flow of the liquid and maintaining the rate of upward flow in the vessel constant, regardless of the rate of withdrawal of the separated particles from the base by feeding the liquid to the Y base of the vessel through a connection having an overflow chamber.

3. In an apparatus for classifying solid particles and depositing the same from a liquid in which they are carried, a vessel having a series of corrugated partitions arranged so as to have their apices in contact to form a series of parallel vertical passages of re stricted cross section in combination with means for feeding the liquid below the partitions and withdrawing it from above the same, and an over-flow for controlling the hydrostatic head between the feed and withdrawal points.

4. In an apparatus for classifying solid particles and depositing the same from a liquid in which they are carried, a vessel having a series'of partitions arranged to forma series of parallel vertical passages of restricted cross section with means connected to an over-flow for feeding liquid containing solid particles into said vessel below said partitions, but above the collecting area for the separated particles.

5. The method of classifying out in suceessive vessels particles of decreasing size suspended in liquid which comprises moving the mixture upwardly successively through similar vessels with decreasing upward velocEty in the-successive vessels without addition of other liquid and controlling separately the volume of mixture which enters each vessel and the amount of separated particles evacuated from each vessel.

(3. The method of separating solid particles out of liquid carrying the same, which comprises feeding the liquid successively into the bases of a-series of vessels, withdrawing it from the upper part of each vessel,

LUCIEN BERGUERAND. 

